Calculation of quark condensate in nuclear matter with the chiral symmetryspontaneous breaking Lagrangian

Using the chiral symmetry spontaneous breaking Lagrangian with mean-field a pproximation, we investigate the in-medium quark condensate <(q) over barq >. It is found that the condensate decreases as the nuclear matter density rho increases. Meanwhile, the desent deviates from the linear decrease and becomes remarkably slow as the density of the nuclear matter further increa ses. It shows that the chiral symmetry spontaneous breaking is only partial ly restored in densed nuclear matter.